Change tcpip.Error to an interface

This makes it possible to add data to types that implement tcpip.Error.
ErrBadLinkEndpoint is removed as it is unused.

PiperOrigin-RevId: 354437314

2 files changed, 14 insertions, 11 deletions

diff --git a/pkg/tcpip/link/sharedmem/sharedmem.go b/pkg/tcpip/link/sharedmem/sharedmem.go
index 6c937c858..2599bc406 100644
--- a/pkg/tcpip/link/sharedmem/sharedmem.go
+++ b/pkg/tcpip/link/sharedmem/sharedmem.go
@@ -203,7 +203,7 @@ func (e *endpoint) AddHeader(local, remote tcpip.LinkAddress, protocol tcpip.Net
 
 // WritePacket writes outbound packets to the file descriptor. If it is not
 // currently writable, the packet is dropped.
-func (e *endpoint) WritePacket(r stack.RouteInfo, _ *stack.GSO, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) *tcpip.Error {
+func (e *endpoint) WritePacket(r stack.RouteInfo, _ *stack.GSO, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) tcpip.Error {
 	e.AddHeader(r.LocalLinkAddress, r.RemoteLinkAddress, protocol, pkt)
 
 	views := pkt.Views()
@@ -213,14 +213,14 @@ func (e *endpoint) WritePacket(r stack.RouteInfo, _ *stack.GSO, protocol tcpip.N
 	e.mu.Unlock()
 
 	if !ok {
-		return tcpip.ErrWouldBlock
+		return &tcpip.ErrWouldBlock{}
 	}
 
 	return nil
 }
 
 // WritePackets implements stack.LinkEndpoint.WritePackets.
-func (*endpoint) WritePackets(stack.RouteInfo, *stack.GSO, stack.PacketBufferList, tcpip.NetworkProtocolNumber) (int, *tcpip.Error) {
+func (*endpoint) WritePackets(stack.RouteInfo, *stack.GSO, stack.PacketBufferList, tcpip.NetworkProtocolNumber) (int, tcpip.Error) {
 	panic("not implemented")
 }
 
diff --git a/pkg/tcpip/link/sharedmem/sharedmem_test.go b/pkg/tcpip/link/sharedmem/sharedmem_test.go
index 23242b9e0..d480ad656 100644
--- a/pkg/tcpip/link/sharedmem/sharedmem_test.go
+++ b/pkg/tcpip/link/sharedmem/sharedmem_test.go
@@ -425,8 +425,9 @@ func TestFillTxQueue(t *testing.T) {
 		ReserveHeaderBytes: int(c.ep.MaxHeaderLength()),
 		Data:               buf.ToVectorisedView(),
 	})
-	if want, err := tcpip.ErrWouldBlock, c.ep.WritePacket(r, nil /* gso */, header.IPv4ProtocolNumber, pkt); err != want {
-		t.Fatalf("WritePacket return unexpected result: got %v, want %v", err, want)
+	err := c.ep.WritePacket(r, nil /* gso */, header.IPv4ProtocolNumber, pkt)
+	if _, ok := err.(*tcpip.ErrWouldBlock); !ok {
+		t.Fatalf("got WritePacket(...) = %v, want %s", err, &tcpip.ErrWouldBlock{})
 	}
 }
 
@@ -493,8 +494,9 @@ func TestFillTxQueueAfterBadCompletion(t *testing.T) {
 		ReserveHeaderBytes: int(c.ep.MaxHeaderLength()),
 		Data:               buf.ToVectorisedView(),
 	})
-	if want, err := tcpip.ErrWouldBlock, c.ep.WritePacket(r, nil /* gso */, header.IPv4ProtocolNumber, pkt); err != want {
-		t.Fatalf("WritePacket return unexpected result: got %v, want %v", err, want)
+	err := c.ep.WritePacket(r, nil /* gso */, header.IPv4ProtocolNumber, pkt)
+	if _, ok := err.(*tcpip.ErrWouldBlock); !ok {
+		t.Fatalf("got WritePacket(...) = %v, want %s", err, &tcpip.ErrWouldBlock{})
 	}
 }
 
@@ -538,8 +540,8 @@ func TestFillTxMemory(t *testing.T) {
 		Data:               buf.ToVectorisedView(),
 	})
 	err := c.ep.WritePacket(r, nil /* gso */, header.IPv4ProtocolNumber, pkt)
-	if want := tcpip.ErrWouldBlock; err != want {
-		t.Fatalf("WritePacket return unexpected result: got %v, want %v", err, want)
+	if _, ok := err.(*tcpip.ErrWouldBlock); !ok {
+		t.Fatalf("got WritePacket(...) = %v, want %s", err, &tcpip.ErrWouldBlock{})
 	}
 }
 
@@ -579,8 +581,9 @@ func TestFillTxMemoryWithMultiBuffer(t *testing.T) {
 			ReserveHeaderBytes: int(c.ep.MaxHeaderLength()),
 			Data:               buffer.NewView(bufferSize).ToVectorisedView(),
 		})
-		if want, err := tcpip.ErrWouldBlock, c.ep.WritePacket(r, nil /* gso */, header.IPv4ProtocolNumber, pkt); err != want {
-			t.Fatalf("WritePacket return unexpected result: got %v, want %v", err, want)
+		err := c.ep.WritePacket(r, nil /* gso */, header.IPv4ProtocolNumber, pkt)
+		if _, ok := err.(*tcpip.ErrWouldBlock); !ok {
+			t.Fatalf("got WritePacket(...) = %v, want %s", err, &tcpip.ErrWouldBlock{})
 		}
 	}